tbuckley/cabot-search huggingface dataset:
Abstract P1088: Polycystin-1 Protects Against Experimental Atrial Fibrillation
Authors: Troy Hendrickson, William Perez, Abigail Giese, Francisco Altamirano
Journal: Circulation Research (2022)

Atrial fibrillation (AF) is the most common cardiac arrhythmia with a 1 in 4 lifetime risk. AF impairs cardiac function and increases the risk of stroke and heart attack. Although this is a common and harmful disease, little is known about the molecular mechanisms driving this disease. We have previously demonstrated that the protein polycystin-1 (PC1) plays a role in atrial cardiomyocyte excitation-contraction coupling in ventricular cardiomyocytes. Interestingly, patients with mutations in PC1 encoding gene have increased rates of atrial arrhythmias, including atrial fibrillation. Here, we sought to study the role of PC1 in atrial cardiomyocyte function and atrial fibrillation inducibility. We performed intracardiac electrophysiology with burst pacing in two mouse models with impaired PC1 function: 1) a mouse model harboring R3277C mutation (RC/RC) known to cause autosomal polycystic kidney disease, and 2) cardiomyocyte-specific PC1 KO (CKO). We observed increased rates of atrial fibrillation inducibility in both RC/RC and PC1 CKO mice compared to their respective control littermates (76.9% in RC/RC and 81.8% in CKO vs 20.0% and 11.1% in their respective WT controls). To elucidate molecular mechanisms driving increased susceptibility to atrial fibrillation, we determined whether PC1 affects excitation-contraction coupling in atrial cardiomyocytes. Human induced pluripotent stem cells-derived atrial cardiomyocytes (hiPSC-aCM) were treated with control or PC1 siRNA. Action potentials and intracellular calcium were measured using Fluovolt and Fluo-4, respectively. PC1 ablation decreased action potential duration and calcium transient peak amplitude elicited by electrical stimulation in hiPSC-CM. Decreased calcium transient peaks were also observed in HL-1 atrial cell line treated with siRNA and adult atrial cardiomyocytes isolated from RC/RC mice compared to their control counterparts. Unexpectedly, RNA-sequencing revealed altered DNA Damage Response gene expression. DNA damage has been implicated in the pathogenesis of atrial fibrillation. Therefore, we studied whether tachypacing elicited DNA damage in hiPSC-aCM. We observed increased levels of H2AX phosphorylation (gamma H2AX) in hiPSC-aCM with reduced PC1 expression. Our data show that PC1 mutations increase atrial fibrillation inducibility in multiple mouse models, likely due to impaired DNA damage response and altered action potential and calcium handling.
Abstract P1097: Heart Rate Variability Analysis In Rodents Reveals Altered Cardiac Autonomic Regulation Following Myocardial Infarction
Authors: Emanuele Pizzo, Silvia Berrettoni, Ridhima Kaul, Daniel O Cervantes, Valeria Di Stefano, Kanwardeep Singh, Sudhir Jain, Jason Jacobson, Marcello Rota
Journal: Circulation Research (2022)

Heart rate variability (HRV) is an index of cardiovascular health and reflects the ability of the heart to modify beating rate in response to neurohumoral factors. Alterations of HRV have been reported in patients with myocardial infarction (MI), but whether experimental models of ischemic disease recapitulate features of HRV observed in human remains to be clarified. HRV was evaluated in female mice using electrocardiograms collected in the conscious, restrained state using a tunnel device. Naïve mice and animals after permanent coronary artery ligation (MI) were studied. HRV was assessed using time-domain, frequency-domain, and non-linear parameters. By echocardiography, all infarcted animals presented akinetic anterior LV free wall and, respect to naïve mice, a 1.8-fold increase in LV diameter and a 64% reduction in ejection fraction. At 3 to ~30 days after MI, RR interval duration was preserved with respect to non-infarcted mice, whereas standard deviation of RR interval duration (SDRR), was reduced by 61-70% at 3 days to ~30 days after MI. Standard deviation of instantaneous (SD1) and long-term (SD2) RR interval variability, indicative of parasympathetic and sympathetic influence, respectively, were derived from Poincaré plots of RR i and RR i+1 intervals. SD1 and SD2 were reduced after MI (64-73% and 61-70%, respectively). Moreover, by frequency-domain analysis, the contribution of high- (1.5-5 Hz), low- (0.15-1.5 Hz), and very low-frequency (0-0.15 Hz) components of RR interval oscillations were assessed. High-frequency components, which are under the influence of the sympathetic nervous system, were not affected after MI; low-frequency oscillations, attributed to baroreflex-mediated modulation of heart rate, were reduced at 3 and 7 days after MI, whereas very low-frequency components, attributed to the modulatory action of the renin-angiotensin system, thermoregulation, and, partly, parasympathetic activity, were reduced from 3-30 days after MI. Moreover, the ratio between low and high frequency components, indicative of sympathovagal balance, was reduced after MI. In conclusion, myocardial infarction in rodent results in altered heart rate variability, which appears to be secondary, in part, to altered autonomic regulation.
HIV-associated non-Hodgkin’s Lymphomas (Literature Review with Own Clinical Cases)
Authors: N. V. Klimova, A. O. Ramzina, A. A. Gaus, I. V. Bazhukhina, Yu. G. Karpenko
Journal: Radiology - Practice (2022)

This article provides a review of the literature on HIV-associated tumors (HATs) such as diffuse large B-cell lymphoma, Burkitt’s lymphoma, plasmablastic lymphoma, and anal canal lymphoma. The presented material is supplemented with own observations and illustrative material.
Abstract P2025: BET Bromodomain Proteins Are Necessary For TGFβ2-Mediated Myofibroblast Activation
Authors: Andrew Antolic, Zhe Jiao, Michael Alexanian, Talha Ijaz, Arun Padmanabhan, Michael A Burke
Journal: Circulation Research (2022)

Fibrosis is a key feature of dilated cardiomyopathy (DCM). Stress signaling triggers the activation of quiescent fibroblasts to myofibroblasts. Bromodomain and extraterminal (BET) epigenetic reader proteins integrate stress-responsive signaling. We explored the role of BETs on distinct inflammatory signaling pathways in cardiac fibroblasts. Fibroblasts were isolated from wild type hearts using the Langendorff procedure. Cell cultures were treated with vehicle, the pan-BET inhibitor JQ1, or siRNA targeting Smad3 or Rela (to inhibit TGFβ and NFκB pathways, respectively) followed by TGFβ2 stimulation. Gene expression was assessed by QPCR, α-smooth muscle actin (αSMA) was quantified by western blot, and NFκB transcription was evaluated using a dual luciferase reporter assay. The interaction between BRD4 and SMAD3 was assessed by coimmunoprecipitation (coIP) in immortalized adult mouse cardiac fibroblast cell cultures treated with TGFβ2, JQ1, or vehicle. TGFβ2-induced fibroblast activation was ablated by JQ1 and Smad3 siRNA (reduced expression of Acta2, Col3a1, Postn and αSMA). CoIP revealed a direct interaction between BRD4 and SMAD3 in fibroblasts, which increased 2.2-fold (p&lt;0.05) after TGFβ2 stimulation. By contrast, Rela siRNA alone induced myofibroblast gene expression ( Acta2 , 6.9-fold; Col3a1 , 7.0-fold; Postn , 11.2-fold; p&lt;0.05 vs. vehicle for all), and increased αSMA levels (2.2-fold; p&lt;0.05). This effect of Rela siRNA was similar to that observed with TGFβ2 stimulation. Further, TGFβ2 inhibited NFκB-driven gene transcription (-2.9-fold; p&lt;0.05 vs. vehicle). These data demonstrate that BRD4 is a critical co-activator of TGFβ2-SMAD3 signaling and cardiac fibroblast activation. We also found that NFκB signaling is downregulated by TGFβ2, suggesting that NFκB may modulate inflammatory gene network activation.
Abstract P1033: A Simple 2-D Assay For Measuring Contraction And Calcium Kinetics In Engineered Human Cardiomyocytes To Model Duchenne Muscular Dystrophy
Authors: Brian L Lin, William Jeffreys, Alex Wu, David A Kass
Journal: Circulation Research (2022)

Duchenne muscular dystrophy (DMD) is caused by the loss of the dystrophin protein, resulting in progressive muscle wasting, loss of ambulation, and early mortality in the second and third decades of life. While the skeletal muscle phenotype is most prominently associated with DMD, heart failure is the leading cause of death in DMD patients, and therapies remain limited. Advancements in stem cell-derived models and assays for heart disease have exciting translational potential for DMD, such as patient-specific modeling and drug screening. Contracting 2-D monolayers and organoids are standards of cardiac engineering, but measuring contraction is challenging due in part due to multi-axial alignment of immature sarcomeres. Complicated solutions to measure contraction in stem cell models use fluorescent beads to infer contraction, transgenic systems that express fluorescent proteins, 3-D scaffolding, and/or custom hardware and software. Here, we utilize a common microscope system used for measuring mature cardiomyocyte (IonOptix) and a commercially-available module (CytoMotion) that measures changes in pixel intensity to index contraction. This platform allows simultaneous measurement of contraction motion and calcium transients just like with adult mammalian cardiomyocytes. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) from a Duchenne muscular dystrophy (DMD) patient and a healthy relative, we demonstrate DMD hiPSC-CM exhibit impaired contraction and calcium handling. We have since further increased the output of our assay using a custom 24-well stimulation plate, and current studies are using this workflow to validate experimental therapies that show promise from mouse models of DMD.
Abstract P3086: Regulation Of Rhoa In Myeloid Cells On Remodeling Of The Infarcted Heart
Authors: Bing Xu
Journal: Circulation Research (2022)

Small GTPase RhoA is critically involved in myocardial injury, repair, and fibrosis. However, the role of RhoA signaling in regulating of macrophage is poorly understand. In this study, we investigated the role of RhoA in macrophage in modulating cardiac function after myocardial infarction and dissected the mechanisms mediating RhoA dependent modulation of macrophage function. RhoA deletion in myeloid cells worsen the cardiac function and lead an increase in post-infarction scar and cardiac fibrosis. RhoA deletion in myeloid cells decreased CCR2 + infiltration in heart, however, increase the circulation of Ly6c hi monocytes in blood expression. RhoA deletion macrophage produce more pro-inflammatory cytokines IL-1β and IL-12b compared to control mice. Mechanistically, CCR2/RhoA axis is critical for CCl2 induced monocytes infiltration. We demonstrated RhoA critically regulates function of infarct macrophage by mediating CCL2 inducing macrophage infiltration and by contributing to proinflammatory transition.
Abstract P2052: Lowered Pro-fibrotic And Damage Associated Molecular Pattern Gene Expressions After Exercise Training In A Mouse Model Of Hypertrophic Cardiomyopathy
Authors: Kristine Andreassen, Chloe Rixon, Marie Haugsten Hansen, Ida Marie Hauge-Iversen, Ivar Sjaastad, Geir Christensen, Kristina H Haugaa, Thor Edvardsen, Ida G Lunde, Mathis K Stokke
Journal: Circulation Research (2022)

Background: Hypertrophic cardiomyopathy (HCM) is the most frequent inherited cardiac disease, most often caused by mutations in sarcomere genes. The disease is characterized by left ventricular (LV) hypertrophy, increased risk of arrhythmias and diastolic dysfunction, due to cardiomyocyte hypercontractility, myocyte disarray and fibrosis. Fibrosis is a marker of worse prognosis, adverse remodeling and an increased risk of sudden cardiac death. Hypothesis: We hypothesized that exercise training could attenuate fibrosis development in mice genetically predisposed to HCM. Methods: We allocated male α-Myh6 R403Q/+ to high intensity interval treadmill running or sedentary behavior (N=11 per group) for a total of 6 weeks. HCM was induced in all mice by cyclosporine A given via the feed for the last 3 of the 6 week exercise protocol. All mice underwent echocardiography and an exercise test at weeks 0, 3, and 6, before harvesting LVs for digital droplet PCR (ddPCR) and a qPCR immune array. Results: Exercise training lead to a 2-fold increase in exercise capacity as measured by total distance ran during exercise testing (p&lt;0.0001). In exercised HCM mice, several key fibrosis-related genes were lowered compared to sedentary HCM mice as measured by ddPCR (N=11 per group): Collagen 1 by 51 % (p=0.03), collagen 3 by 54 % (p=0.02), fibronectin by 51 % (p=0.01) and lysyl oxidase by 42 % (p=0.05). An array of 87 selected immune-related genes showed that 39 genes were upregulated &gt;1.5 fold in sedentary HCM mice compared to sedentary wild type controls (N=3 samples, pooled). Twelve upregulated genes belonged to damage associated-molecular patterns (DAMPs). Several of the DAMP genes were lower in exercised HCM mice compared to sedentary HCM mice (N=10-11 per group): Biglycan was lowered by 29 %, versican by 22 % and fibronectin by 55 %. Trends were also found for lowered expression of syndecan 1 (by 26 %), fibromodulin (by 55 %), and tenacin C (by 49 %) (0.07&lt;p&lt;0.08). There was no difference in maximal wall thickness or function measured by echocardiography. Conclusion: Exercise training led to a lower expression of key fibrosis-related genes in an inducible mouse model of HCM. Initial results indicate that attenuation of DAMP signaling might be involved in the mechanism for this effect.
Abstract P3141: Human Milk Oligosaccharide Attenuates Lipopolysaccharide-induced Endothelial Hyperpermeability And Migration
Authors: Dung Van Nguyen, Lila Kim, Kyung-Sun Heo
Journal: Circulation Research (2022)

Background: Endothelial hyperpermeability plays a crucial role in the initial development of vascular inflammation, resulting in endothelial dysfunction. Human milk oligosaccharide (HMO), is the bioactive product, is recognized to protect against obesity and anti-inflammatory activity, but it is unknown what effects and signaling pathways are in endothelial cell (EC) function. Therefore, we examined the hypothesis that the protection of HMO in stabilizing endothelial barrier function as well as improving the cell migration under LPS treatment. Methods and Results: We analyzed the effect of HMO on the permeability and migration of cultured Bovine aortic endothelial cells (BAECs). Our results found that HMO significantly suppressed the expression of phosphorylated ERK1/2 and p38 MAPK but not JNK after exposure to LPS. In addition, immunofluorescence staining revealed that HMOs abolished the nuclear translocation of NF-κB and phosphorylated STAT3, which was accompanied by down-regulation of pro-inflammatory cytokines and chemokines such as TNF-α, IL-1β, MCP-1, VCAM-1, and ICAM-1 under LPS stimulation. Our data demonstrated an improvement of endothelial barrier function as indicated in PECAM-1 endothelial junction as well as an enhancement of cell migration by HMO pre-treatment, followed by LPS treatment. Conclusion: Our results suggest that HMO as a potential therapeutic agent for the reduction of microvascular leakage and inflammation in vascular disease.
Abstract P1115: SnoRNAs As Potential Biomarkers For Assessment Of Health Risks In Astronauts
Authors: Amit Rai, K. Shanmugha Rajan, Malik Bisserier, Agnieszka Brojakowska, Aimy Sebastian, Angela Evans, Matthew Coleman, Paul Mills, Arsen A Arakelyan, Shizuka Uchida, Lahouaria Hadri, David A Goukassian, Venkata Garikipati
Journal: Circulation Research (2022)

During spaceflight, astronauts are exposed to various physiological and psychological stressors, such as microgravity, sleep deprivation, isolation, confinement, and high ionizing radiation have shown adverse health effects. Therefore, there is an unmet need to develop novel diagnostic tools to predict early alterations in astronauts' health. Small nucleolar RNA (snoRNA) is a type of short ncRNAs (60-300 nucleotides) known to guide 2’-O-methylation (Nm) or pseudouridine (ψ) on ribosomal RNA (rRNA), snRNA, or mRNA. Emerging evidence suggests that dysregulated snoRNAs may be key players in regulating fundamental cellular mechanisms and the pathogenesis of cancer, heart, and neurological disease. Therefore, we sought to determine whether the spaceflight-induced snoRNA changes in plasma extracellular vesicles (EV) and astronaut's peripheral blood mononuclear cells (PBMCs) can be utilized as potential biomarkers. Using unbiased small RNA sequencing (sRNAseq), we evaluated the EV snoRNA changes in peripheral blood (PB) plasma of astronauts (n=5/group) who underwent median 12-day long Shuttle missions between 1998-2001. Using stringent cutoff (&gt; log 2-fold change, FDR &lt; 0.05), we detected 20 down-regulated snoRNAs and 10 upregulated PB-EVs at R+3 compared to L-10. qPCR validation revealed that SNORA74A was significantly down-regulated at R+3 compared to L-10. We next determined snoRNA expression levels in astronauts' PBMCs at R+3 and L-10 (n=6/group). qPCR analysis further confirmed a significant increase in SNORA19 and SNORA47 in astronauts' PBMCs at R+3 compared to L-10 Notably, many downregulated snoRNA-guided rRNA modifications, including four Nms and five ψs. Our findings unveiled that spaceflight induced changes in EV and PBMCs snoRNA expression, thus suggesting snoRNAs may serve as novel biomarkers for monitoring astronauts' health.
Abstract OEC101: Cardiac Reprogramming Inducer ZNF281 Is Indispensable For Heart Development By Interacting With Key Cardiac Transcriptional Factors
Authors: Hisayuki Hashimoto, Jin Komuro, Takahiro Nakamura, Shinsuke Yuasa, Keiichi Fukuda
Journal: Circulation Research (2022)

During direct cardiac reprogramming, cardiogenic transcription factors (TFs) cooperatively reshape the epigenomic landscape by activating cardiac enhancers, which describe a common epigenetic signature between in vitro cardiac reprogramming and in vivo heart development. We thus hypothesized that direct reprogramming could be a useful tool to study novel transcriptional regulators in heart development. To test this hypothesis, we focused on ZNF281/Zfp281(Zinc finger protein 281), a pluripotency regulator which showed up as an unexpected strong cardiac reprogramming inducer from our previous unbiased screen. Since Zfp281 is an essential factor for epiblast maturation, we established a Zfp281 floxed mouse line using CRISPR/Cas9 system to study the impact of Zfp281 after cardiac lineage commitment. We then generated multiple conditional Zfp281KO (cKO) mouse lines by crossing with different stage-specific Cre driver lines. Surprisingly, we found that mesodermal (Mesp1-Cre) Zfp281cKO mice were embryonic lethal as early as E9.5, associated with various cardiac anomalies. In contrast, cardiac progenitor (Nkx2-5-Cre) and cardiomyocyte (Myh6-Cre) Zfp281cKO mice survived to adulthood and appeared grossly normal, suggesting a crucial role of Zfp281 in mesodermal to cardiac differentiation. Next, we performed RNA-seq analysis to study the molecular mechanism of Zfp281 deficient cardiac anomalies. Interestingly, expression of cardiac TFs and sarcomeric genes were altered in Zfp281cKO embryos compared to control siblings. Consistently, co-immunoprecipitation analysis showed direct interaction of Zfp281 with Mesp1 and Gata4. These data indicate that Zfp281 directly interacts with cardiac TFs to cooperatively orchestrate the cardiogenic transcriptional network. In conclusion, by using multiple genetic mouse models, we discovered that cardiac reprogramming inducer Zfp281 plays a pivotal role in heart development. Although GWAS studies have identified various disease-causing mutations, the etiology for the majority of congenital heart disease remains largely unknown and there are still such missing pieces to be uncovered in the interdependent cardiogenic transcriptional network. Our study demonstrates and highlights the impact and possibility of direct reprogramming as a novel approach to study cardiovascular biology.
Abstract P1043: Myocardial Infarction Induces Translocation Of Gut Bacteria To The Heart
Authors: Tushar Madaan, Michelle Nieman, Nabil Siddiqui, John Lorenz, Sakthivel Sadayappan, Nalinikanth Kotagiri
Journal: Circulation Research (2022)

Introduction: Myocardial hypoxia &amp; intestinal hyperpermeability (IH) are two important events commonly observed in the aftermath of a myocardial infarction (MI) event. Recent studies have shown that gut bacteria and their metabolites are able to leak into the systemic circulation due to post-MI IH. Hypothesis: We hypothesized that facultative anaerobic gut bacteria such as E. coli will be able to translocate and colonize the hypoxic heart post-MI. Methods: C57 mice were given an oral administration of 10e9 cfu of luciferase/GFP expressing E. coli Nissle (EcN). Permanent occlusion of LAD arteries was performed to induce MI. Mouse hearts were checked for presence of EcN using PCR at different timepoints (n=32), IHC (n=4), and siderophore-based PET imaging (n=2). Immunoblotting of heart tissue lysate was used to check for presence of GFP. Results: PCR amplification of DNA extracted from MI hearts of mice given oral EcN revealed cardiac presence of translocated EcN. IHC analysis further confirmed presence of EcN in the heart. Siderophore-based PET imaging &amp; radionuclide-based biodistribution studies revealed significantly higher uptake in the MI heart vs. Sham corroborating EcN presence. Immunoblotting revealed presence of GFP in cardiac tissue of MI mice suggesting that bacterial products and proteins could potentially translocate through the gut-heart axis. Conclusion: MI induced IH &amp; myocardial hypoxia contribute to the translocation of gut bacteria and colonization of the ischemic heart.